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\begin{document}

\title{Successful treatment of suspect Babesia-induced ARDS in a dog using
lung-protective positive-pressure ventilation and neuromuscular
blockade.}



\author[1]{Ian DeStefano}%
\author[2]{Annie Wayne}%
\author[3]{Sarah Cudney}%
\author[1]{Elizabeth Rozanski}%
\affil[1]{Tufts University Cummings School of Veterinary Medicine}%
\affil[2]{Ethos Veterinary Health}%
\affil[3]{ACCESS Specialty Animal Hospitals}%


\vspace{-1em}



  
  \date{May 28, 2024}


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\selectlanguage{english}
\begin{abstract}
A mixed breed dog was treated for severe hemolytic anemia secondary to
Babesia canis infection. Within 14 hours of hospitalization, the dog
developed respiratory distress and hypoxemia. The patient improved with
lung-protective mechanical ventilation and neuromuscular blockade. The
dog survived to discharge and was reportedly healthy at three-month
follow up.%
\end{abstract}%



\sloppy


\textbf{Abstract --} A mixed breed dog was treated for severe hemolytic
anemia secondary to \emph{Babesia canis} infection. Within 14 hours of
hospitalization, the dog developed respiratory distress and hypoxemia.
The patient improved with lung-protective mechanical ventilation and
neuromuscular blockade. The dog survived to discharge and was reportedly
healthy at three-month follow up.

\textbf{}

\textbf{INTRODUCTION}

Babesiosis is a tick-borne infection caused by several parasitic
hematoprotozoal organisms belonging to the \emph{Babesia} genus. Several
pathogenic species have been documented in dogs, but in the United
States, \emph{B. canis} and \emph{B. gibsoni} are most
common.\textsuperscript{1-3} Transmission occurs through a variety of
mechanisms, such as the bite of an infected \emph{Rhiphecephalus
sanguineus} tick, transplacental and direct blood-blood contact, dog
bites, and contaminated blood transfusion.\textsuperscript{1} A variety
of clinical syndromes in dogs and people with babesiosis have been
described, and the hallmark is hemolytic anemia or ``uncomplicated
babesiosis.''\textsuperscript{1} Immune-mediated hemolysis, increased
erythrocyte osmotic fragility, direct cellular injury by piroplasms, and
oxidative injury have all been proposed as causes of
hemolysis.\textsuperscript{1}

In addition to anemia, other severe clinical syndromes have been
described in people and dogs.\textsuperscript{4-7} Sequelae of
babesiosis unrelated to hemolysis are termed ``complicated babesiosis,''
and are associated with worse prognosis.\textsuperscript{4} There are no
consensus definitions of complicated vs. uncomplicated babesiosis in
veterinary medicine, but complicated infections may include sequelae
like pancreatitis, acute kidney injury, cerebral babesiosis, or
hepatopathy.

\emph{Babesia} -induced acute respiratory distress syndrome (ARDS) is a
late and rare complication of human babesiosis cases, first reported in
1984 as a single case report\textsuperscript{5} and not again until
1994.\textsuperscript{6} The incidence of \emph{Babesia} -induced ARDS
in dogs is unknown, partially because case reports documenting
respiratory distress in this population do not report diagnostic
information to evaluate for ARDS criteria. However, several studies have
shown poor outcome in dogs with complicated babesiosis that include
respiratory signs, as well as histologic evidence of ARDS in a dog with
cerebral babesiosis.\textsuperscript{4,8,9} The successful management of
severe respiratory failure and suspected ARDS in a dog with naturally
occurring babesiosis has not previously been described.

\textbf{CASE REPORT}

\textbf{Clinical history:}

An approximately 11-week-old intact male mixed breed dog was presented
to the emergency service as a referral for severe anemia and suspected
babesiosis. The dog had a history of being transported from Texas three
weeks prior. One week after transport, the dog was evaluated by his
primary veterinarian for acute onset of lethargy, where he was febrile
(40.4\selectlanguage{ngerman}°C) with an otherwise normal physical exam. An in-house complete
blood cell count (CBC) showed a severe microcytic (MCV 61 fL, reference
interval {[}RI{]} 61.6-73.5 fL), normochromic (MCHC 347 g/L, RI 320-379
g/L), non-regenerative (reticulocyte count 6.3x10\textsuperscript{9}/L,
RI 10.0-110.0 x10\textsuperscript{9}/L) anemia (HCT 0.147 L/L, RI
0.373-0.617 L/L), as well as a normal leukocyte (6.29
x10\textsuperscript{9}/L, RI 5.05-16.76 x10\textsuperscript{9}/L) and
neutrophil count (4.57 x10\textsuperscript{9}/L, RI 2.95-11.84
x10\textsuperscript{9}/L), and severe thrombocytopenia (platelet count
23 x10\textsuperscript{9}/L, RI 148-484 x10\textsuperscript{9}/L). The
dog was treated with 15 mL/kg of packed red blood cells (pRBC) over 4
hours. He was discharged home having also received 150 mL of
subcutaneous fluids (unknown type), and prescribed omeprazole (10 mg PO
q 24 h), sucralfate (1 gram PO q 8 h), and amoxicillin/clavulanate (10
mg/kg PO q 12 h; Clavamox, Zoetis). The fever had improved (39.4°C)
before discharge. The following day he was returned to the referring
hospital for recheck, where a packed cell volume (PCV) was 23\%. Eight
days later, the dog re-presented to his primary veterinarian due to
lethargy, and a PCV was 15\%. An in-house blood smear evaluation was
suspicious for \emph{Babesia} , so polymerase chain reaction (PCR)
testing was submitted to a reference laboratory. The dog was discharged
home with clindamycin (75 mg PO q 12 h). The next day, the owner
reported that the dog was too weak to stand, prompting referral.

\textbf{Examination and treatment}

On presentation, the dog was quiet and non-ambulatory. Physical exam
indicated pallor with mild icterus and splenomegaly on abdominal
palpation. The dog weighed 5.75 kilograms and was normothermic (38.2°C).
He was tachycardic (150 beats/minute) and tachypneic (60 breaths/minute)
with normal bronchovesicular and heart sounds on auscultation.
Point-of-care bloodwork showed severe anemia (PCV 14\%) and low
refractometric serum total protein (TP, 5.4 g/dL). A venous blood
gas/electrolyte panel (NOVA Stat Profile, Nova Biomedical, Waltham,
Massachusetts, USA) was consistent with compensated metabolic acidosis
with elevated lactate (5.2 mmol/L). Point-of-care ultrasound evaluation
of the heart and lungs showed subjective volume contraction and no
effusions or pulmonary B-lines were noted. Abdominal point-of-care
ultrasound was unremarkable other than subjective splenomegaly. The dog
was blood typed (DEA 1.1 positive) and major cross-matched, then
admitted to the ICU. He was initially treated with 1 mg/kg IV maropitant
(Cerenia, Zoetis, Kalamazoo, Michigan, USA), then was transfused with 14
mL/kg of pRBCs.

CBC and chemistry analysis were performed (see Tables 1 and 2), and
cytologic evaluation of a blood smear by a boarded clinical pathologist
showed intra-erythrocytic piroplasms morphologically consistent
with\emph{Babesia canis} . The dog was treated with 6.6 mg/kg IM
imidocarb (Imizol, Merck, Kenilworth, New Jersey, USA) and was started
on IV fluids (Lactated Ringer's solution, Baxter, Deerfield, Illinois,
USA) at 75 mL/kg/day. After completion of the blood transfusion, a
PCV/TP showed no improvement of his anemia (PCV 13\%, TP 5.0), and
progressive hyperlactatemia (8.2 mmol/L). The dog was noted to be more
alert, was ambulatory and eupneic (36 breaths/min) but febrile (39.4°C).
He was given 2.2 mg/kg diphenhydramine IM (West-Ward, Eatontown, New
Jersey, USA) due to concern for a transfusion reaction and an additional
13 mL/kg pRBC were administered over 6 hours. Fourteen hours after
admission the dog became tachypneic (RR \textgreater{}100 breaths/min)
and was transferred to an oxygen chamber to provide approximately 40\%
fractional inspired oxygen (FiO\textsubscript{2}). An hour later he
developed diarrhea and hypersalivation, so he was given 0.02 mg/kg
atropine IV due to concern for parasympathetic signs as an adverse
effect of imidocarb. Over the next hour his tachypnea worsened,
necessitating emergent endotracheal intubation using IV propofol (Abbot
Animal Health, Chicago, Illinois, USA).

During intubation, a large volume of serosanguineous/icteric fluid was
produced through the endotracheal tube. Initial manual ventilation using
an anesthetic machine and 100\% FiO\textsubscript{2} yielded
SpO\textsubscript{2} values 88-92\%. He was then switched to mechanical
ventilation (MV) using a commercial ventilator (Puritan Bennett 840,
Medtronix, Minneapolis, Minnesota, USA). Initial ventilator settings are
listed in Table 3 (hour 0). Sedation was maintained with titrated
continuous rate infusions (CRIs) of fentanyl (Hospira Inc., Lake Forest,
Illinois, USA) at 5-10 mcg/kg/hr, midazolam (West-Ward) at 0.1-1
mg/kg/hr, and dexmedetomidine (Dexdomitor, Zoetis) at 1 mcg/kg/hr. An
indwelling urinary catheter was placed, and urine output was adequate
(2.3 mL/kg/hr over 12 hours).

Initially, the dog's pulmonary static compliance was poor (0.7 mL/cm
H\textsubscript{2}O/kg, normal range 1-1.6 mL/cm H\textsubscript{2}O/kg)
and normoxemia measured by pulse oximetry (SpO\textsubscript{2}) was
achieved only with aggressive ventilator settings (see Table 3) and high
FiO2 (80\%). Arterial catheterization/blood gas samples were not
obtained due to the dog's thrombocytopenia and coagulopathy noted on
point-of-care coagulation parameters (prothrombin time 20 seconds, RI
12-17 seconds; activated partial thromboplastin time \textgreater{}300
seconds, RI 72-102 seconds). Blood titers were submitted to a reference
lab to evaluate for co-infection with \emph{Borrelia} , ehrlichiosis,
anaplasmosis, and \emph{Rickettsia rickettsii} . A 6 French, 90-cm
nasogastric tube (Mila, Florence, Kentucky, USA) was placed and the dog
was started on enteral doxycycline (10 mg/kg q 24 h; PuraCap, Laurelton,
New York, USA). Repeat point-of-care lung ultrasound showed confluent
B-lines bilaterally with no evidence of left atrial enlargement as
determined by the LA:Ao ratio.

The dog's PCV improved and remained stable throughout the day (23-24\%),
although he developed marked jaundice. He remained normothermic and
normotensive but was dyssynchronous with the ventilator and was assessed
to be in a relatively light plane of sedation. Additional sedation was
added with a CRI of ketamine (Hospira Inc.) at 0.5 mg/kg/hr and propofol
at 0.1-0.5 mg/kg/min titrated to effect. Adequate sedation/synchrony was
achieved, and ketamine was discontinued within a few hours.

After 10 hours on MV, the dog developed progressive hypercapnia
(ETCO\textsubscript{2} 55 mmHg). While troubleshooting, his endotracheal
tube was sterilely suctioned and produced a large amount of
icteric/serosanguineous fluid, which was cytologically consistent with a
neutrophilic exudate and rare intracellular bacteria. Hand-held
refractometry of the fluid showed a TP of 4.8 g/dL (peripheral TP was
5.6 g/dL). A sample of the fluid was submitted for aerobic culture and
piperacillin/tazobactam (50 mg/kg IV q 6 h; Auromedics, East Windsor,
New Jersey, USA) was started. The dog then developed hypotension (mean
arterial pressure {[}MAP{]} 65 mmHg) which was initially responsive to a
fluid challenge (10 mL/kg Lactated Ringer's solution). At 12 hours on
MV, hypotension recurred (MAP 44 mmHg) coupled with relative oliguria
(urine output 1.5 mL/kg/hr). There was no improvement with another fluid
challenge (5 mL/kg), so a norepinephrine (Claris Lifesciences, North
Brunswick, New Jersey, USA) CRI was started at 0.2-0.6 mcg/kg/minute
titrated to achieve a MAP of \textgreater{}70 mmHg and systolic blood
pressure \textgreater{}100 mmHg.

At 13 hours on MV, the dog developed poor oxygen saturation
(SpO\textsubscript{2} 89\%, FiO\textsubscript{2} 60\%) and frequent
tachypnea despite adequate sedation (no response to physical/auditory
stimuli). An arterial blood gas showed severe hypoxemia and hypercapnia
(Table 3). Ventilator settings were adjusted using a modified version of
the ARDSnet protocol (see Table 4) and were titrated to meet a minimum
SpO\textsubscript{2} \textgreater{}92\%. He was also given 0.1 mg/kg
dexamethasone (Dexaject SP, Henry Schein, Melville, New York, USA) IV
once. The dog's SpO\textsubscript{2} mildly improved initially, but he
continued to have significant tachypnea despite adjusting ventilator
settings to address dyssynchrony. A propofol bolus IV was given to
effect to induce complete apnea, after which his oxygen saturation
substantially improved (SpO\textsubscript{2} 98\%); the decision was
made to induce neuromuscular blockade with atracurium (Sagent,
Schaumberg, Illinois, USA) 0.3 mg/kg IV, followed by a CRI (6-9
mcg/kg/min) which rapidly improved his ventilator synchrony. Persistent
hypercapnia occurred after neuromuscular blockade was started
(ETCO\textsubscript{2} 60-65 mmHg) but maintained adequate oxygenation.

At 24 hours on MV, ventilator settings had been gradually weaned while
maintaining SpO2 \textgreater{}93\%. Portable thoracic radiographs
(Figure 1) showed a bilateral mixed pulmonary interstitial and alveolar
lung pattern which was worse in the left lung lobes (attributed to
atelectasis per a board-certified veterinary radiologist). Diagnostic
considerations included ARDS or transfusion-related acute lung injury
(TRALI).

At 48 hours on MV, the dog was on minimal ventilator settings (Table 3).
Atracurium was discontinued and norepinephrine was weaned/discontinued.
Within hours, the other sedative infusions were also discontinued
(fentanyl/midazolam/propofol), and his dexmedetomidine was lowered to
0.5 mcg/kg/hour. He was extubated and left to fully recover from
sedation in an oxygen cage with 30\% FiO\textsubscript{2}. Several hours
later, oxygen supplementation was discontinued. Results of the pending
infectious disease titers showed ehrlichiosis co-infection. His urinary
catheter was removed, and he walked with mild support.

\textbf{Outcome and follow-up:}

On day 4 of hospitalization the nasogastric tube was removed, and the
dog was discharged with amoxicillin/clavulanate (14 mg/kg PO q 12 h;
Clavamox, Zoetis), maropitant (1 mg/kg PO q 24 h; Cerenia, Zoetis), and
doxycycline (5 mg/kg PO q 12 h). The airway culture was positive for low
numbers of oropharyngeal contaminants (quantitatively reported as
``few''), so amoxicillin/clavulanate was continued for a total of 7
days. The \emph{Babesia} PCR testing was positive for \emph{Babesia
canis vogeli} . Fourteen days after the initial imidocarb injection, the
dog was represented for recheck and was clinically well. A CBC showed
improved regenerative anemia, resolved thrombocytopenia and
leukocytosis, and no \emph{Babesia} organisms (see Table 1). A second
dose of imidocarb (6.6 mg/kg IM) was given without any adverse events.
The dog had complete resolution of disease and was still doing well
three months later.

\textbf{Discussion:}

To the authors' knowledge, this report details the successful management
of hypoxemic respiratory failure in a dog with complicated babesiosis.
While definitive evidence of ARDS was not obtained with histopathology,
it remains a likely differential diagnosis. Reports of management of
suspected ARDS are scarce in the veterinary literature, and this report
provides clinical guidance for such patients.

Acute respiratory distress syndrome (ARDS) describes the complex
clinical syndrome of lung injury leading to downstream consequences of
activation of cell-mediated immune pathways, endothelial injury, and
alveolar flooding with protein-rich edema.\textsuperscript{10,11} This
initial ``exudative'' phase of lung injury can be initiated secondary to
several pulmonary and extra-pulmonary risk factors, but ultimately leads
to increased vascular permeability, pulmonary edema, atelectasis,
impaired gas exchange/hypoxemia, and respiratory fatigue often requiring
positive pressure ventilation. Consensus definitions of acute lung
injury and ARDS have been proposed previously for small
animals.\textsuperscript{12} Based on these criteria, the authors
propose that the dog described here fulfilled VetARDS criteria based on
the following: (1) acute onset (\textless{}72 hours) tachypnea, (2)
known risk factors (infection/sepsis, multiple transfusions), (3) and
pulmonary capillary leak as evidenced by bilateral lung infiltrates on
thoracic radiographs, proteinaceous fluid within the conducting airways,
and no echocardiographic evidence supporting cardiogenic pulmonary
edema. The fourth criterion, evidence of inefficient gas exchange, was
not directly documented at the time of respiratory decline but arterial
blood gases sampled after 12 hours of MV showed a profound hypoxemia and
coupled with the findings of poor oxygen saturation immediately after
intubation, prior to MV inefficient gas exchange was undoubtedly
present.

The case presented here did have growth of oropharyngeal contaminant
microbes on airway culture, but concurrent aspiration pneumonia cannot
be completely ruled out. Several other factors make bacterial pneumonia
less likely: the radiographic pulmonary changes were not classic for
aspiration pneumonia, the patient presented afebrile, had normal lung
sounds, and the tachypnea at presentation resolved after initial pRBC
transfusion.

Respiratory failure in people with babesiosis that meet ARDS criteria is
unique from other forms of ARDS because of its delayed onset and
relatively rapid resolution when compared to more typical causes. One
patient who survived severe hypoxemic respiratory failure with
initiation of MV was extubated on the 10\textsuperscript{th} day of
treatment and discharged on day 20.\textsuperscript{4} Another describes
a babesiosis-associated ARDS patient who was extubated on day 4 of
hospitalization.\textsuperscript{6} The dog described here was on MV for
approximately 2 days, with discharge on day 5 of hospitalization and
developed suspect ARDS several weeks into his disease course.
Respiratory compromise possibly attributable to ARDS has been documented
in 6\% of dogs with complicated babesiosis in one study, and only one
dog was reported to recover, representing 3.2\% (1/31) of complicated
infections and 1.6\% (1/63) of all infections.\textsuperscript{9} While
the relative severity of respiratory compromise was not specified in the
manuscript, all dogs were treated with oxygen
supplementation.\textsuperscript{9} In one retrospective canine study of
complicated babesiosis, 38\% (32/84) of dogs died, of which 56\% (18/32)
had respiratory failure as the listed cause of
death.\textsuperscript{4}Another report of respiratory distress and
mental obtundation in a dog with babesiosis had histopathology changes
consistent with ARDS on necropsy.\textsuperscript{9} Interestingly,
previous reports noted that\emph{B. canis vogeli} is associated with
less severe disease except in the subpopulation of very young
dogs,\textsuperscript{3} which fits the scenario presented here.

In people, ARDS historically carried a mortality rate of 40-50\%, but
trials in the last 20 years have shown improved outcomes with
``lung-protective'' ventilation strategies that include high PEEP and
low tidal volumes to avoid alveolar overdistention and
atelectrauma,\textsuperscript{13} prone
positioning,\textsuperscript{14}neuromuscular
blockade,\textsuperscript{15} and early use of
corticosteroids\textsuperscript{16} in certain subgroups of patients.
There are no studies specifically evaluating ventilation strategies of
ARDS and their impact on outcome in dogs. The dog in the present report
was managed with ventilation settings adapted from the human ARDSnet
trial.\textsuperscript{13} In this case, use of PEEP titrated to
FiO\textsubscript{2} requirements combined with neuromuscular blockade
resulted in rapidly improved hypoxemia and pulmonary compliance. For the
majority of the patient's MV, a slightly higher tidal volume (55 mL,
\textasciitilde{}9.6 mL/kg) was used than the lung-protective tidal
volumes from ARDSnet. It is unknown whether the same tidal volumes used
in people with ARDS should be applied to dogs, as the proportion of
lung:body weight may differ. The tidal volume in this patient was not
reduced further due to hypercapnia.

At the time of initiation of neuromuscular blockade, the dog was
considered heavily sedated. It is standard of care in people to meet
certain criteria of sedation prior to using paralytic agents for MV,
such as the Richmond agitation-sedation score
{[}RASS{]}.\textsuperscript{17} Ensuring a RASS of -4 to -5 (deep or
unarousable sedation, respectively) helps avoid inadvertent awake
paralysis in ventilated patients, which may cause ICU delirium and
post-traumatic stress disorder from intensive
care.\textsuperscript{16}While human sedation criteria applied to dogs
have not been evaluated, we would have scored the dog a RASS of -5
despite being tachypneic/dyssynchronous with the ventilator. The amount
of sedation provided was not changed while the dog was paralyzed to
avoid awake paralysis, but an optimal strategy to determine proper
sedation prior to neuromuscular blockade remains unclear for dogs.

The present case report has several important limitations. Confirmation
of ARDS with histopathology and full echocardiography by a cardiologist
were not performed. Given that the dog responded with the therapy
described and tolerated IV fluid administration, the authors feel that
cardiovascular fluid overload is unlikely. Transfusion-related acute
lung injury cannot be ruled out, though a blood type and crossmatch were
performed prior to transfusion. In people this complication is more
commonly associated with products containing soluble antibodies such as
fresh frozen plasma, but activation of primed resident pulmonary
leukocytes by other blood products secondary to severe systemic
inflammation is another proposed mechanism.\textsuperscript{18} While we
suspect that respiratory failure was already developing prior to blood
transfusion, this cannot be proven. Regardless, receiving multiple
transfusions is listed as a risk factor for ARDS in people as well as
the veterinary consensus definition.\textsuperscript{12}

\textbf{Conclusion:}

We present here a case of suspected ARDS associated with \emph{Babesia
canis vogeli} infection in a young dog with successful application of
some ARDSnet lung-protective strategies in MV and favorable outcome.
While this dog made a full recovery, veterinary clinicians should be
vigilant of this potential complication of babesiosis, and know that
while successful treatment is possible, more data are necessary to
comment on the prognosis and applications of lung-protective MV in dogs
with suspected ARDS.

\textbf{Author Contributions:}

Ian M DeStefano: contributed to acquisition and evaluation of case
material as well as drafting, revision and final approval of the
manuscript.

Annie S Wayne: contributed to revision and final approval of the
manuscript.

Sarah E Cudney: contributed to revision and final approval of the
manuscript.

Elizabeth A Rozanski: contributed to revision and final approval of the
manuscript.

\textbf{Acknowledgement:}

None.

\textbf{References} :

\begin{enumerate}
\tightlist
\item
  Birkenheuer AJ. Babesiosis. In: Sykes JE, editors. Canine and Feline
  Infectious Diseases. 1\textsuperscript{st} ed. St. Louis: Elsevier
  Saunders; 2014, pp. 727-738.
\item
  Boozer LA, Macintire DK. Canine babesiosis. Vet Clin Small Anim 2003;
  33: 885-904.
\item
  Zahler M, Schein E, Rinder H, et al. Characteristic genotypes
  \selectlanguage{english}discriminate between Babesia canis isolates of differing vector
  specificity and pathogenicity to dogs. Parasitol Res 1998;
  84:544--548.
\item
  Welzl C, Leisewitz AL, Jacobson LS, et al. Systemic inflammatory
  response syndrome and multiple-organ damage/dysfunction in complicated
  canine babesiosis. J South Afr Vet Assoc 2001; 72: 158-162.
\item
  Gordon S, Cordon RA, Mazdzer EJ et al. Adult respiratory distress
  syndrome in babesiosis. Chest 1984; 86: 633-634.
\item
  Horowitz ML, Coletta F, and Fein AM. Delayed onset adult respiratory
  distress syndrome in babesiosis. Chest 1994; 106(4): 1299-1301.
\item
  Panduranga V, Kumar A. Severe babesiosis presenting as acute
  respiratory distress syndrome in an immunocompetent patient. Crit Care
  Med 2012; 40(12-S1): 1-328.
\item
  M\selectlanguage{ngerman}áthé Á, Vörös K et al. Clinical manifestations of canine babesiosis
  in Hungary (63 cases). Acta Vet Hung 2006; 54(3): 367-385.
\item
  Daste T, Lucas M, Aumann M. Cerebral babesiosis and acute respiratory
  distress syndrome in a dog. J Vet Emerg Crit Care 2013; 23(6):
  615-623.
\item
  Taylor TB, Chambers RC, Liu KD. Acute respiratory distress syndrome. N
  Engl J Med 2017; 377(6): 562-572.
\item
  Ranieri VM, Rubenfield GD, Thompson BT et al. Acute respiratory
  distress syndrome: the Berlin Definition. JAMA 2012; 307(23):
  2526-2533.
\item
  Wilkins PA, Otto CM, Baumgardner JE, et al. Acute lung injury and
  acute respiratory distress syndromes in veterinary medicine: consensus
  definitions: the Dorothy Russell Havemeyer Working Group on ALI and
  ARDS in veterinary medicine. J Vet Emerg Crit Care 2007; 17(4):
  333-339.
\item
  Brower RG, Matthay MA, Morris A et al. Ventilation with lower tidal
  volumes as compared with traditional tidal volumes for acute lung
  injury and the acute respiratory distress syndrome. N Engl J Med 2000;
  342(18):1301-1308.
\item
  Gue\selectlanguage{english}rin C, Reignier J, Richard J-C, et al. Prone positioning in severe
  acute respiratory distress syndrome. N Engl J Med 2013; 368:
  2159-2168.
\item
  Papazian L, Forel J-M, Gacouin A et al. Neuromuscular blockers in
  early acute respiratory distress syndrome. N Engl J Med 2010;
  363:1107-1116
\item
  The National Heart, Lung, and Blood Institute Acute Respiratory
  Distress Syndrome (ARDS) Clinical Trials Network. Efficacy and safety
  of corticosteroids for persistent acute respiratory distress syndrome.
  N Engl J Med 2006; 354:1671-1684.
\item
  Sessler CN, Gosnell MS, Grap MJ et al. The Richmond agitation-sedation
  scale: validity and reliability in adult intensive care unit patients.
  Am J Respir Crit Care Med 2002; 166(10): 1338-1344.
\item
  Marik PE, Corwin HL. Acute lung injury following blood transfusion:
  Expanding the definition. Crit Care Med 2008; 36(11):3080-3084.
\end{enumerate}

\textbf{Table 1.} Serial CBC values at hospital admission (day 0),
during hospitalization (day 2) and at follow-up (day 14).\selectlanguage{english}
\begin{longtable}[]{@{}llllll@{}}
\toprule
Complete Blood Cell Count & & & & &\tabularnewline
\midrule
\endhead
\textbf{Parameter (units)} & \textbf{Day 0} & \textbf{Day 2} &
\textbf{Day 4} & \textbf{Day 14} & \textbf{Reference
Interval}\tabularnewline
\textbf{WBC count (x10\textsuperscript{9}/L)} & 19.89 & 39.73 & 22.23 &
11.81 & 4.4 -- 15.1\tabularnewline
\textbf{HCT (L/L)} & 0.14 & 0.21 & 0.21 & 0.32 & 0.39 --
0.55\tabularnewline
\textbf{MCV (fL)} & 69.8 & 71.6 & 72.9 & 70.5 & 64.5 --
77.5\tabularnewline
\textbf{MCHC (g/L)} & 3.09 & 3.41 & 3.04 & 3.06 & 3.19 --
3.43\tabularnewline
\textbf{RDW (L/L)} & 0.161 & 0.159 & 0.229 & 0.163 & 0.119 --
0.152\tabularnewline
\textbf{Platelet count (x10\textsuperscript{9}/L)} & 70 & 99 & 252 & 314
& 173 -- 486\tabularnewline
\textbf{Mean platelet volume (fL)} & 23.6 & 20.3 & 15 & 11.3 & 8.29 --
13.2\tabularnewline
\textbf{Reticulocytes (x10\textsuperscript{9}/L)} & 181.5 & 262.1 &
394.2 & 121.1 & 14.7 -- 113.7\tabularnewline
\textbf{Neutrophils (x10\textsuperscript{9}/L)} & 14.8 & 31.6 & 13.42 &
6.84 & 2.8 -- 11.5\tabularnewline
\textbf{Lymphocytes (x10\textsuperscript{9}/L)} & 4.4 & 6.4 & 6.6 & 3.72
& 1 -- 4.8\tabularnewline
\textbf{Monocytes (x10\textsuperscript{9}/L)} & 0.8 & 1.6 & 1.98 & 0.36
& 0.1 -- 1.5\tabularnewline
\textbf{Band neutrophils (x10\textsuperscript{9}/L)} & 0 & 0.4 & 0 & 0 &
0 -- 0.3\tabularnewline
\textbf{nRBC (/100 WBC)} & 1 & 5 & 2 & 2 & 0 -- 1\tabularnewline
\textbf{Parasites} & \emph{B. canis} & None & None & None &
None\tabularnewline
\bottomrule
\end{longtable}

HCT = hematocrit; MCV = mean corpuscular volume; MCHC = mean corpuscular
hemoglobin concentration; nRBC = nucleated red blood cells; RDW = red
cell distribution width; WBC = white blood cell count

\textbf{Table 2.} Serial serum chemistry values.\selectlanguage{english}
\begin{longtable}[]{@{}llllll@{}}
\toprule
Chemistry Profile & & & & &\tabularnewline
\midrule
\endhead
\textbf{Parameter (units)} & \textbf{Day 0} & \textbf{Day 2} &
\textbf{Day 4} & \textbf{Day 14} & \textbf{Reference
Interval}\tabularnewline
\textbf{Glucose (mmol/L)} & 4.6 & 6.3 & 7.2 & & 3.7 --
7.5\tabularnewline
\textbf{Urea nitrogen (mmol/L)} & 10.35 & 11.07 & 1.07 & & 2.86 --
10.71\tabularnewline
\selectlanguage{greek}\textbf{Creatinine (µmol/L)}\selectlanguage{english} & 26.52 & 17.68 & 26.52 & & 53.04 --
176.80\tabularnewline
\textbf{Phosphorus (mmol/L)} & 2.93 & 1.29 & 1.97 & & 0.84 --
2.33\tabularnewline
\textbf{Calcium (mmol/L)} & 2.6 & 2.4 & 2.4 & & 2.35 --
2.83\tabularnewline
\textbf{Magnesium (mmol/L)} & 1.0 & 0.95 & 0.8 & & 0.9 --
1.5\tabularnewline
\textbf{Total Protein (g/L)} & 48 & 36 & 40 & & 55 -- 78\tabularnewline
\textbf{Albumin (g/L)} & 22 & 12 & 16 & & 28 -- 40\tabularnewline
\textbf{Globulin (g/L)} & 26 & 24 & 24 & & 23 -- 42\tabularnewline
\textbf{Sodium (mmol/L)} & 148 & 146 & 144 & & 140 -- 150\tabularnewline
\textbf{Chloride (mmol/L)} & 110 & 114 & 109 & & 106 --
116\tabularnewline
\textbf{Potassium (mmol/L)} & 5.2 & 3.2 & 4.9 & & 3.7 --
5.4\tabularnewline
\textbf{Anion Gap (mmol/L)} & 21 & 12 & 10 & & 8 -- 19\tabularnewline
\selectlanguage{greek}\textbf{Total Bilirubin (µmol/L)}\selectlanguage{english} & 5.13 & 107.73 & 20.52 & & 1.71 --
5.13\tabularnewline
\textbf{ALP (U/L)} & 131 & 234 & 523 & & 12 -- 127\tabularnewline
\textbf{GGT (U/L)} & \textless{}1 & 3 & 2 & & 0 -- 10\tabularnewline
\textbf{ALT (U/L)} & 37 & 259 & 118 & & 14 -- 86\tabularnewline
\textbf{AST (U/L)} & 114 & 83 & 31 & & 9 -- 54\tabularnewline
\textbf{Creatine kinase (U/L)} & 535 & 856 & 318 & & 22 --
422\tabularnewline
\textbf{Cholesterol (mmol/L)} & 3.83 & 6.06 & 5.31 & & 2.12 --
9.19\tabularnewline
\textbf{Triglycerides (mmol/L)} & 0.63 & 22.49 & 1.00 & & 0.34 --
3.82\tabularnewline
\bottomrule
\end{longtable}

ALP = alkaline phosphatase; ALT = alanine aminotransferase; AST =
aspartate aminotransferase; GGT = gamma-glutamyltransferase

\textbf{Table 3} - Ventilator settings and patient vitals over the
course of mechanical ventilation. A volume-control mode in SIMV with
pressure support was used throughout the course of treatment.\selectlanguage{english}
\begin{longtable}[]{@{}llllllllllll@{}}
\toprule
\textbf{Time (hours)} & \textbf{0} & \textbf{2} & \textbf{13*} &
\textbf{14} & \textbf{16} & \textbf{18} & \textbf{24} & \textbf{28} &
\textbf{36} & \textbf{42} & \textbf{50**}\tabularnewline
\midrule
\endhead
\textbf{F\textsubscript{set} (breaths/min)} & 15 & 15 & 25 & 25 & 25 &
25 & 25 & 25 & 25 & 25 & 1\tabularnewline
\textbf{F\textsubscript{tot} (breaths/min)} & 103 & 102 & 25 & 25 & 25 &
25 & 54 & 34 & 25 & 25 & 24\tabularnewline
\textbf{V\textsubscript{t} (mL)} & 60 & 50 & 55 & 55 & 55 & 55 & 55 & 55
& 55 & 55 & 40\tabularnewline
\textbf{PS (cmH\textsubscript{2}O)} & 10 & 10 & 8 & 8 & 8 & 8 & 8 & 2 &
2 & 2 & 2\tabularnewline
\textbf{PEEP (cmH\textsubscript{2}O)} & 8 & 6 & 10 & 10 & 10 & 10 & 8 &
8 & 5 & 5 & 3\tabularnewline
\textbf{PIP (cmH\textsubscript{2}O)} & 15 & 17 & 22 & 24 & 18 & 16 & 20
& 14 & 14 & 16 & 7\tabularnewline
\textbf{P\textsubscript{mean} (cmH\textsubscript{2}O)} & 9.9 & 9.8 & 15
& 14 & 11 & 9.3 & 12 & 10 & 9 & 8 & -\tabularnewline
\textbf{C (mL/cmH\textsubscript{2}O)} & 3.6 & 3.9 & 2.5 & 3.8 & 4.8 &
7.2 & 6 & 8.1 & 6.7 & 5.0 & -\tabularnewline
\textbf{C\textsubscript{wt} (mL/cmH\textsubscript{2}O/kg)} & 0.7 & 0.75
& 0.48 & 0.73 & 0.92 & 1.38 & 1.15 & 1.56 & 1.29 & 0.96 &
-\tabularnewline
\textbf{I:E ratio} & 1:1.1 & 1:1.3 & 1:1.9 & 1:1.9 & 1:1.8 & 1:1.9 &
1:1.2 & 1:1.9 & 1:1.9 & 1:1.9 & -\tabularnewline
\textbf{FiO\textsubscript{2}} & 1.0 & 0.6 & 0.6 & 0.6 & 0.6 & 0.6 & 0.5
& 0.4 & 0.4 & 0.4 & 0.3\tabularnewline
\textbf{SpO\textsubscript{2} (\%)} & 96 & 93 & 89 & 92 & 95 & 94 & 94 &
93 & 93 & 93 & 95\tabularnewline
\textbf{ETCO\textsubscript{2} (mmHg)} & 49 & 39 & 71 & 74 & 57 & 51 & 35
& 35 & 60 & 65 & -\tabularnewline
\textbf{PvCO\textsubscript{2} (mmHg)} & 50 & - & - & - & - & - & - & - &
- & 55 & -\tabularnewline
\textbf{PaCO\textsubscript{2} (mmHg)} & - & - & 60 & - & - & - & - & - &
- & - & -\tabularnewline
\textbf{PaO\textsubscript{2} (mmHg)} & - & - & 84 & - & - & - & - & - &
- & - & -\tabularnewline
\textbf{P:F ratio} & - & - & 140 & - & - & - & - & - & - & - &
-\tabularnewline
\bottomrule
\end{longtable}

Time intervals presented in units of hours from presentation. HR = heart
rate (beats/minute); F\textsubscript{set}=mandatory respiratory rate
(breaths/minute); F\textsubscript{tot} = total respiratory rate
(breaths/minute); V\textsubscript{t} = tidal volume; PS = pressure
support applied to spontaneous breaths; PEEP = positive end-expiratory
pressure; PIP = peak inspiratory pressure; C = static compliance;
C\textsubscript{wt} = static compliance indexed for body weight in
kilograms; I:E ratio = inspiratory to expiratory ratio;
FiO\textsubscript{2} = fractional inspired oxygen concentration;
SpO\textsubscript{2} = pulse oximetry; ETCO\textsubscript{2} = end-tidal
carbon dioxide; PvCO\textsubscript{2} = venous carbon dioxide tension;
PaCO\textsubscript{2} = arterial carbon dioxide tension;
PaO\textsubscript{2} = arterial oxygen tension; P:F ratio =
PaO\textsubscript{2}:FiO\textsubscript{2} ratio. * = prior to adopting
ARDSnet settings; ** = immediately prior to extubation.

\textbf{Table 4 -} Positive end-expiratory pressure and fractional
inspired oxygen settings used, adapted from the ARDSnet
trial.\textsuperscript{10}\selectlanguage{english}
\begin{longtable}[]{@{}lllllllllllllll@{}}
\toprule
\textbf{FiO\textsubscript{2}} & 0.3 & 0.4 & 0.4 & 0.5 & 0.5 & 0.6 & 0.7
& 0.7 & 0.7 & 0.8 & 0.9 & 0.9 & 0.9 & 1.0\tabularnewline
\midrule
\endhead
\textbf{PEEP (cmH\textsubscript{2}O)} & 5 & 5 & 8 & 8 & 10 & 10 & 10 &
12 & 14 & 14 & 14 & 16 & 18 & 18-24\tabularnewline
\bottomrule
\end{longtable}

FiO\textsubscript{2} = fractional inspired oxygen concentration; PEEP =
positive end-expiratory pressure.

\textbf{Figure legends:}

\textbf{Figure 1.} Thoracic radiographs taken 24 hours after intubation.
Dorsoventral (a) and right lateral views (b).\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Picture1/Picture1}

\end{center}
\end{figure}

\selectlanguage{english}
\FloatBarrier
\end{document}

